The present invention relates to a multistage rotary switch with several switch wafers, with each switch wafer comprising a case member with laterally inserted fixed contacts and a rotor with the swivel-type contacts, with the stacked case members forming a multistage rotary switch with a closed casing.
From DE-AS No. 2 617 606 there is known a multi-section cam switch having a closed casing in which a moulded plate is provided for between the individual case members. This moulded plate is to have moulded portions cooperating with the matching recesses provided for in the case members. How these moulded portions are designed and what purpose the moulded plates serve, cannot be discerned from the cited reference.
In a multistage rotary switch as known from DE-OS No. 2 355 175, each switch wafer consists of a disk having a central bore in which the rotor is arranged in the same plane. On the rim portions of the disk, at two almost diagonally opposite points, there are provided hooks projecting in one direction. Accordingly, this multistage rotary switch has no closed casing. The projecting hooks engage into the disk of the following switch wafer. For serving as an anti-rotation means and for enabling an exact stacking, a pin is moulded on the side opposite the hook, which engages into a corresponding recess of the switch wafer disk arranged on the other side. The rotor is fixed in the axial direction by the contact spring assemblies arranged on both sides of the disk or the rotor.
The present invention is aimed at solving, amongst others, the problem of enabling in the case of a multistage rotary switch of the type mentioned hereinbefore, an exact stacking of the component parts and, at the same time, especially in the case of switches comprising many switch wafers, of keeping the torque which is necessary for operating the switch as small as possible.